Within the context of modern data centers there is a need to provide for uninterrupted power to protected load devices that are serviced by power supply units (PSU). The PSU architecture described in U.S. patent applications incorporated by reference herein (Ser. No. 14/461,110 and Ser. No. 14/509,454) may be configured in a variety of ways to ensure that this requirement for uninterrupted protected load power supply is achieved. The present invention describes a variety of power supply failover systems/methodologies to achieve this desired result.